Android 网络请求框架解析之okhttp与okio

<?xml version="1.0" encoding="utf-8"?>
<network-security-config>
    <!--禁用掉明文流量请求的检查-->
    <base-config cleartextTrafficPermitted="true" />
</network-security-config>

android:networkSecurityConfig="@xml/nettools"

<uses-permission android:name="android.permission.INTERNET" />
    <uses-permission android:name="android.permission.READ_EXTERNAL_STORAGE" />
    <uses-permission android:name="android.permission.WRITE_EXTERNAL_STORAGE" />
    <uses-permission android:name="android.permission.ACCESS_NETWORK_STATE" />```

import androidx.annotation.UiThread;
import androidx.appcompat.app.AppCompatActivity;

import android.os.Bundle;
import android.util.Log;
import android.view.View;
import android.widget.Button;
import android.widget.TextView;

import java.io.IOException;

import okhttp3.OkHttpClient;
import okhttp3.Request;
import okhttp3.Response;

public class MainActivity extends AppCompatActivity {
    private Button btn;
    private TextView txt;

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);
        initView();
    }

    private void initView() {
        btn = findViewById(R.id.btn);
        txt = findViewById(R.id.txt);
        btn.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View view) {
                request();
            }
        });
    }

    protected void request() {
        new Thread(new Runnable() {
            @Override
            public void run() {
                OkHttpClient client = new OkHttpClient();
                Request request = new Request.Builder()
                        .url("https://www.baidu.com")
                        .build();

                Response response = null;
                String string = null;
                try {
                    response = client.newCall(request).execute();
                    string = response.body().string();
                } catch (
                        IOException e) {
                    e.printStackTrace();
                }

                String finalString = string;
                runOnUiThread(new Runnable() {
                    @Override
                    public void run() {
                        txt.setText(finalString);
                    }
                });
            }
        }).start();
    }
}

<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    android:orientation="vertical">

    <Button
        android:id="@ id/btn"
        android:layout_width="match_parent"
        android:layout_height="wrap_content" />

    <ScrollView
        android:layout_width="match_parent"
        android:layout_height="match_parent">

        <TextView
            android:id="@ id/txt"
            android:textSize="20sp"
            android:layout_width="match_parent"
            android:layout_height="wrap_content" />

    </ScrollView>

</LinearLayout>